Objective: To investigate the molecular epidemiology of carbapenem-resistant Acinetobacter baumannii-calcoaceticus complex isolates in a tertiary care hospital where the prevalence of carbapenem resistance among these organisms is high.
Design: The study was a prospective, observational study performed during an 8-month period (May 1 through December 31, 2004). A. baumannii isolates recovered from all clinical samples during the study period were included in the study. Antibiotic susceptibility testing was performed using the disk diffusion method, and all carbapenem-resistant strains were typed by a polymerase chain reaction-based typing method.Setting. An 800-bed hospital in Singapore.
Results: More than half of recovered isolates were clonally unrelated, with the remaining isolates grouped into 4 genotypes.
Conclusions: The results of the study suggest that the high prevalence of carbapenem resistance among Acinetobacter organisms in this institution is not caused by the spread of a predominant clone and that other factors may need to be investigated.